Exposed wiring is dangerous. Whether you are running electricity to a garage, outdoor outlet or an extra plug in your shop, those wires need to be protected. PVC conduit will provide the protection required. It is inexpensive and simple to install. The time spent running the conduit and pulling your wires through it will be well spent. It will reduce the risk of short circuits and extend the useful life of the wiring.
Check with your local code enforcement office before performing any electrical wiring. Use only approved wire and conduit for your job. Once you have determined the proper sizes of wiring and conduit, measure the distance of the proposed run. Look for any obstacles you may encounter. Advance planning and route inspection can save time and possibly another trip to the home improvement store.
Shut off all electrical power before you do any wiring. If your proposed run begins at the service panel, shut off the panel's main breaker. Use a large screwdriver and pliers to remove an appropriate knockout plug on the service panel. Measure and cut the first section of conduit. A PVC cutter will leave a clean, square cut. If you use a hacksaw, use sandpaper to remove the burr at the end of the tube. Secure the end of the conduit to the panel with a locknut. Use clamps to secure the conduit to the wall every four feet or as necessary. To join sections of conduit for a watertight fit, brush pipe-cleaning/primer solvent on the outside of the conduit and the inside of the joining bell or fitting. Then brush glue on both of the cleaned surfaces. Push the ends of the joint together as soon after applying the glue as possible. If you plan to run wiring underground, your trench should be deeper than the frost line for your area. In areas without a frost line, the trench should be at least 12 inches deep. Avoid laying conduit on top of rocks or other hard or sharp objects.
Tie a small weight to the end of a roll of mason's line. Feed the line through each section of conduit as you glue it together. After you have finished running your conduit, you can use the line to pull your wires back through the conduit. If your conduit will be exposed to direct sunlight, a coat of exterior latex house paint will protect the PVC from UV light damage. Using a level to make all exposed conduit runs square and plumb will give your job a professional appearance.